Guys, humans aren't made of cast iron and a body is only about a 12" deep, give or take. The heart and lungs sit only a couple of inches behind the rib cage. It's not like you have to smash through a heavy bone and muscle to get to the vital organs of a human. It's not especially hard to kill a human being.
Not to turn it into caliber wars, but I posted a video a while back with a medical professional discussing the very topic. He had x rays in his lecture of 9mm being stopped by the victims ribcage. That's always stuck with me. I carry 45+p and 357s, but I'm large enough and have enough experience to handle and shoot them with some degree of proficiency. I also don't believe in double taps. My wife's carry gun has 9mm Barnes solid copper hollow points in it because that's what she feels comfortable with. Not that it matters or has to do with anything, just my personal choice. Just sayiin' YMMV, 0.02 IMO.